chuck wrote:
So we have at least two candidate causes for what is called by some
"precipitation static": charged particles physically impinging on the
antenna wire; and electrostatically induced charges that produce corona
discharges.

Precipitation static requires static transferred from charged
particles of rain, snow, or dust. Corona requires the ionization
of air. These two phenomena can exist together or separately.
Ionization of air requires a certain threshold. Precipitation
static can exist either below or that threshold or be the cause
of the corona. Corona can exist in the absence of precipitation
static. There are other kinds of static, e.g. propagating EM
static from numerous sources.
--
73, Cecil, w5dxp.com